Petroleum lubricants stabilized against hydrocarbon metabolizable microor-ganisms



United States Patent PETROLEUM LUBRICANTS STABILIZED AGAINST IYDREvI'ISARBON METABOLIZABLE MICROOR- Edward B. Hodge, Terre Haute, Ind., assignor to Commercial Solvents Corporation, Terre Haute, Iud., a corporation of Maryland No Drawing. Application August 1, 1957 Serial No. 675,529

a claims. 01. 252-515 My invention relates to a stabilized petroleum lubricant and more particularly to a process for the production of stabilized petroleum lubricants containing as the active stabilizing agent compounds having the following structural formula:

where X is selected from the group consisting of hydrogen and bromine, R is selected from the group consisting of methyl and ethyl and R is selected from the group consisting of aryl, substituted aryl and heterocyclic.

It is well known that organisms from the group consisting of Corynebacterium, Achromobacter, Nocardia, Pseudomona and Mycobacterium metabolize petroleum hydrocarbons and fatty acids and thereby produce undesirable oxidation products.

The petroleum industry has long been interested in the stabilization of various petroleum products such as cutting oils, hydraulic fluids, etc. against break-down by bacteria which metabolize the hydrocarbons with the concurrent formation of deleterious metabolites.

Many compounds have been used as stabilization agents in lubricants, but very few have been found to be commercially successful due to the fact that the compounds are unstable, or are not active against a wide variety of microorganisms.

Among the active compounds which are useful in my invention are 2-nitro-2-bromo-l-methoxy-1-phenylbutane, 2 bromo-l-p-chlorophenyl-1-methoxy-2-nitropropane, 2- bromo 1 ethoxy-Z-nitro-l-phenylpropane, 2 bromo-lmethoxy-1-p-methoxyphenyl-2-nitrobutane, 1-( 2 furyl)- 2-bromo-1-methoxy-2-nitropropane, 1-(2,4-dichlorophenyl)-l-methoxy-2-nitrobutane, 1 (2 pyridyl)-2-bromo-1- methoxy-Z-nitropropane, etc. Of these compounds, I prefer to utilize 2-nitro-2-bromo-l-methoxy-l-phenylpropane as it is very active against petroleum metabolizing bacteria, while being relatively inexpensive. These compounds can be easily prepared in good yields by the method set out in US. Patent 2,742,395.

I have found that in some instances I can obtain total inhibition of bacterial growth in petroleum lubricants at concentrations as low as 0.005%. I prefer to include at least 0.0075 in most petroleum formulations. However, I can employ amounts up to 10.0% of the active agent when the latter is soluble to this extent in the particular petroleum hydrocarbon compositions.

The active ingredients of my invention are effective bacteriostatic agents in petroleum containing lubricants such as cutting oils, penetrating oils, grinding lubricants, iron tinning lubricants, core oils, hydraulic fluids, etc.

The following examples set outlubricating compositions in which my active ingredients are efiective bacteriostatic agents. It is not intended that my invention be limited to the compositions, portions, or lubricants set out below, but rather I intend for all the equivalents and variations obvious to those skilled in the art to be included within the scope of this specification and the attached claims.

Percent by weight Light mineral oil 85 Oleic acid 10 2-amino-2-methyl-l-propanol 5 Two equal portions of this formulation were prepared and enough 2-nitro-2-bromo-1-methoxy-l-phenylpropane to create a 750 'y/ml. concentration was added to one portion. Both portions were then diluted 1:10 with North Gelatin Agar (Difco) and streaked with an 18 hour agar slant culture of the representative organism Pseudomonas aeruginosa. The control and the stabilized composition were then incubated for 18 hours at 35 C. and the growth recorded. No growth was exhibited on the stabilized composition while a growth of 4+ was noted on the control composition.

Example I] A steam cylinder oil having the following composition:

S.A.E. lubricating oil percent 90 Oleic acid do 10 2 nitro 2 bromo-l-propoxy-l-phenylpropane 'y/ml 750 was diluted and tested as shown in Example I. The stabilized composition was found to exhibit no bacterial growth while the control composition exhibited a growth of 4+.

Example III A core oil having the following composition:

Crude tall oil percent 25 Fuel oil do 35 Tall oil ester (glycol or glycerol) do 40 2-bromo'- 1 (3,4-dichlorophenyl) 1 methoxy-Z- nitrobutane 'y/ml 1000 was diluted and tested as shown in Example I and found to exhibit no bacterial growth while the 'control composition exhibited a growth of 4+.

was diluted and tested by the method of Example I and found to exhibit no bacterial growth while a control composition exhibited a growth of 4+.

Now having described my invention, what I claim is: 1. A petroleum hydrocarbon oil of lubricating viscosity stabilized against hydrocarbon metabolizable microorganisms containing in a small but suflicient amount to inhibit a bacterial growth in said petroleum lubricant a compound having the following structural formula R NO:

where X is selected from the group consisting of hydrogen and bromine, R is selected from the group consisting of methyl and ethyl and R is selected from the group consisting of aryl, chloro and methoxy substituted ml and heterocyclic.

2. An aliphatic petroleum hydrocarbon oil of lubricating viscosity stabilized against hydrocarbon metabolizable microorganisms containing from 0.005% to 10.0% by weight of a compound having the structural formula:

consisting of aryl, chloro and methoxy substituted aryl and heterocyclic.

4 3. An aliphatic petroleum hydrocarbon oil of lubricating viscosity stabilized against hydrocarbon metabolizable microorganisms containing 0.0075 to 10.0% of a compound having the structural formula:

of methyl and ethyl and R is selected from the group consisting of aryl, chloro and methoxy substituted aryl and heterocyclic.

References Cited in the file of this patent UNITED STATES PATENTS 2,562,151 Senkus July 24, 1951 2,742,395 Hodge et a1. Apr. 17, 1956 20 2,780,598 Cafcas Feb. 5, 1957 OTHER REFERENCES Fundamentals of Microbiology, by Frobisher, 5th ed., 1953, W. B. Saunders Co., p. 3. 

1. A PETROLEUM HYDROCARBON OIL OF LUBRICATING VISCOSITY STABILIZED AGAINST HYDROCARBON METABOLIZABLE MICROORGANISMS CONTAINING IN A SMALL BUT SUFFICEINT AMOUNT TO INHIBIT BACTERIAL GROWTH IN SAID PETROLEUM LUBRICANT A COMPOUND HAVING THE FOLLOWING STRUCTURAL FORMULA 